It is common knowledge that household fireplaces are generally inefficient as far as room heating is concerned. Most of the heat goes up the chimney rather than into the room. The heat generated in the conventional fireplace which does enter the room enters only by radiation. This heat is quite intense immediately in front of the fireplace; however, the air a few feet from the fireplace is hardly warmed. Generally, therefore, fireplaces as found in private dwellings are used more for their aesthetic appearance than their heating quality.
With the increasing cost of energy, the public has also demanded that their fireplaces become more efficient heat sources while keeping pollution to a minimum. Catalysts have been developed to answer some of these needs, but are expensive and have a limited life span. Additionally, most catalytic combustion systems operate at relatively low temperatures, thereby generating smoke which makes the combustion process unattractive to watch.
Another feature of the catalytic wood burners, is that it is generally necessary to have a heat exchanger, and a blower system to extract the heat. These add to the expense and complexities of the wood burners.
To obtain the efficiency associated with catalytic wood burners without the limitation of such designs, conventional wood burners have been designed to have a refractory lining. Examples of such a design are shown in U.S. Pat. Nos. 4,131,104; 4,154,211; 4,236,500; and 4,240,399 which disclose of front loading refractory lined wood burners having a top baffle heat exchanger. These wood burners, however, are not lined with insulating material, have no glass front to observe the fire, require a costly and complex system of multiple baffle means to cool the combustion gases before they reach the fire, are not inclined to eliminate the need for refractory material clips and create a hopper effect, does not have an automatically adjustable flue damper, and has metal directly exposed to the combustion.